Anyone own a 7mm 300 Win Mag?

Looks real nice John! I got an email from Robert Gradous about 3 weeks ago, said that he had two older builds ahead of mine, and then it was my turn, super excited about getting my 7-300WM!
 
Hey all,

So I had a 7-300 win built for me by Rbros rifles late last year and love everything about it! I love it so much I wanted to build one for my Dad. I called PTG and talked with Dave and ordered a 7-300 win reamer with no shoulder changes and a long throat for a 180 vld. I got an email with the print, and I'm no pro at reading prints, but everything looked great. First pic is that print
Screenshot 2015-03-09 20.28.13.png

Six days later I got another email from PTG with what I thought was the same print, but it said 7mm pratical. I didn't look it over very well, and now I notice that it has a 30 degree shoulder.
Screenshot 2015-03-09 20.30.57.png
I should have called, but I didn't (first time ordering a wildcat reamer, and PTG customer service has been difficult in the past).


The reamer showed up, I gave it to my gunsmith and he cut the chamber. A 300 win go gauge closes in the chamber just fine, but I couldn't get the brass I had prepared to chamber. On closer inspection, I realized that the reamer does have a 30 degree shoulder angle and a longer neck. Looking at the print, its very similar to the balistic studies 7mm Practical but with a longer throat.

SO, my question is this. I feel like the chamber needs to be cut deeper to acomodate a 30 degree shoulder, but if the go gauge fits as it is, it seems obvious that cutting the chamber deeper would create some serious headspace issues. My thought would be to take the brass I prepared for my other 7-300 that chambers just fine, and cut the problem chamber deep enough to chamber my prepared brass. Then would the brass not fire-form to a 30 degree shoulder and I could continue life as normal with my redding type s neck die?? Any comments would be greatly appreciated.
Thanks
 
You have a different chambering than a 7mm-300 win mag. Headspace on belted magnums is checked with a very short go - no go gauge. This gauge fits between the bolt face and the belted portion in the chamber. It doesn't have anything to do with the shoulder.

I compared the 7mm-practical base to shoulder dimension vs the 7mm-300 win mag. The 7 practical appears to be .210" shorter.

I would try to contact the designer for some help:

Email: [email protected]

Here is a link to his discussion with the 7 Practical:

7mm Practical

if you cannot find Nate then I would also talk to Dave Kiff. Bet he knows what you need to do.
 
The rifle you had chambered by RBros is probably the 7 Rogue
The brass will not be interchangeable with the 7-300 or 7 Practical.
The 7 Rogue reamer is proprietary, so you will either need to send the rifle to RBros for rechambering so you can use the same brass in both rifles. Or just keep the brass separated for each rifle.
 
The rifle you had chambered by RBros is probably the 7 Rogue
The brass will not be interchangeable with the 7-300 or 7 Practical.
The 7 Rogue reamer is proprietary, so you will either need to send the rifle to RBros for rechambering so you can use the same brass in both rifles. Or just keep the brass separated for each rifle.


Jim,
I built him a straight 7mm-300, not the Rogue. Looks like PTG messed up and sent him the wrong reamer when he asked for a straight 7-300WM. I mentioned in his other thread, the only way to fix it is to set the barrel back a couple turns and then rechamber with the reamer he wanted. I didn't do the build in question.
 
I have been reading through this post for the last several days. First off, all I can say is WOW. this has to be the longest running post on the net. Second I would like to ask a question. I have a 7/300 rogue in the works. Brass availability is still slim. Has anyone been using Hornady brass in the 7mm practical or 7/300? Forgive me if I am asking a question that has been mentioned already. Also hoe does the weight of the Hornady compare to Remington or Winchester? thanks
 
Hi there, regarding the brass question, I would take Win or Hornady over Remington brass. Nevertheless, I have used Remington brass in the Practical with success. The case capacity is slightly greater than others- but the case head is also quite soft. The net result is that you end up with the same velocities.
 
Both RWS and Norma can have lower case capacity than the likes of Winchester. Norma brass is also very soft. Norma / Nosler can at times display very thick necks, enough to spike pressures when necked to 7mm.
 
Sorry for these ongoing rerplies, I am only just reading past questions.

Regarding the 30 degree shoulder, it has no bearing on how prepped brass chambers. Simply neck .300 brass to 7mm and away you go. If your ammo does not chamber, either the chamber is out of spec or more than likely, you have bumped the shoulder or stressed the case in some way during neck sizing and expanded the case body. The fix will be to run the cases through a .300 or .338 Win mag body die as the tight spot will be just behind the shoulder- not at the shoulder.

I named the wildcat the "7mm Practical" because it is supposed to be an easy straight forwards proposition, not an ordeal. So try to keep this in mind if such problems occur.

While we are on the subject of simple and practical, I should also mention that Lee currently have sample cases for the Practical chamber and can make collet dies if anybody wishes to utilize Lee custom neck collet dies for the Practical.

Hope that helps.
 
Hi Kev, a standard Federal 210 works just fine with these powder charges. The 210 is an already hot primer. Nevertheless, you can change to magnum primers as a part of experimentation if need be, enabling slight alteration or manipulation of powder burn rate which in turn will effect pressures and harmonics. Barrel length is also a factor. The longer the barrel, the more burn you will get with the likes of the F210. CCI offers similar primers.
 
I have read this entire thread several times and searched. I see very little info on primers. What is the most common primer for the 7-300 with H1000 and 180 hybrids? I can't seem to find any 210s. I have BR2s, 250s, and 215Ms. I plan on seating the hybrids .015 off the lands and doing a ladder test with H1000. I would really prefer not to waste barrel life testing primers.
 
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